The equation to work out the speed is distance/time.
If we apply this equation to your numbers we will first need to find the total distance travelled.
80km/h for an hour means you travel 80km
40km/h for 2 hours means you will travel 80km
80+80 is 160km in total.
The time taken to complete this distance is 3 hours so, applying the equation we get
speed = 160/3 = 52.33km/h
Answer:
The speed of elevator fast and slows down shows through the diagram.
Explanation:
Given that,
Amanda has just entered an elevator. The elevator rises and stops at the third floor.
Let us consider the elevator at rest then the speed will be zero.
When elevator start from rest then the speed increases with constant acceleration and near the third floor it slow down with constant deceleration and finally becomes at rest at third floor.
We need to draw the diagram distance and time
Using given data,
First, the displacement A to B will be increases fastly and B to C the displacement increases slowly slowly.
Hence, The speed of elevator fast and slows down shows through the diagram.